1. Field of the Invention
This invention relates to an improved coating pan assembly for coating ingestible pharmaceutical products. More specifically, this invention relates to an improved coating pan spray arm assembly which provides reduced head loss, better distribution and a lower risk of catastrophic leakage than spray arm assemblies which have been used in the past.
2. Description of the Prior Art
Currently available coating pans for medicament preparation include spray assemblies for applying coatings to tablets, for example, sugar coatings. Such coating pan assemblies are discussed in U.S. Pat. No. 4,844,001 to Jones, the disclosure of which is hereby incorporated into this document as if set forth fully herein.
In systems such as that disclosed in the Jones patent, a coating solution is sprayed onto uncoated pharmaceutical product with atomizing nozzles, which are mounted on arms which project through an access door to an interior of the coating pan. The coating solution, atomizing air, and control air are delivered to the nozzles with a manifold of tubing and fittings.
Although such systems are, in general, reliable, random failure of the solution tubing and fittings can sometimes result in leakage of solution onto the pharmaceuticals. When this happens, the entire lot of pharmaceuticals must be discarded. In addition, sagging of the distribution tubes and head loss caused by the tubes and fittings in the prior art spray arm assembly created the potential for non-uniform distribution of solution to the atomizing nozzles.
It is clear that there has existed a long and unfilled need in the prior art for an improved spray arm assembly for coating ingestible pharmaceutical products, which is less subject to leakage-causing failure, which provides a more uniform distribution of coating solution, and which is less subject to fluid pressure loss than the spray arm assemblies heretofore known.